WHAT IS GASTRIC ACID SECRETION TEST (GASTRIC ACID STIMULATION TEST)?
Gastric acid is secreted by the parietal cells of the stomach in response to neurologic and hormonal stimulation. Gastric acid is secreted during the gastric phase of digestion and aids in the breakdown of proteins and in the absorption of vitamin B12, folic acid, and iron. It consists of hydrochloric acid (HCl), electrolytes, enzymes, and mucus. It is colourless and very acidic, with a pH of <2.5. In the presence of tumours, ulcerative disease, or pernicious anaemia, the rate of gastric acid secretion by the parietal cells can be altered. A diagnostic gastric acid stimulation test involves aspirating and collecting basal and maximal acid outputs. Histalog (betazole, a histamine analogue) or histamine diphosphate is injected intramuscularly to stimulate gastric acid secretion. By measurement of the rate and volume of gastric acid, the gastric function can be evaluated.